The present invention generally relates to a facsimile machine and more particularly, to a facsimile machine which uses an ISDN (Integrated Services Digital Network) basic interface as a communication means.
Recently, ISDNs have been put in good condition, and data terminal equipment has been in practical use. A facsimile machine which performs image information transmission through an ISDN is a group-4 (G4) facsimile machine. Standard equipment functions thereof have been recommended by CCITT.
According to the CCITT recommendation to a group-4 facsimile machine, a single signal channel (D channel) for a line exchange processing to one subscriber line, and two information channels (B channels) for data transmission are multiplexed.
However, a conventional group-4 facsimile machine is equipped with only one transmission function. Therefore, it is impossible to perform image information transmission in which the two information channels are used at the same time or in parallel. Further, broadcast transmission which employs the group-4 facsimile machine is executed by the following procedure. First, a document image to be transferred is read and then stored in a memory. Second, a plural number of designated designations is serially called out, and the stored image is serially transferred to the called-out designations. Thus, it takes long to complete broadcast transmission.